This blog discusses current weather, weather prediction, climate issues, and other topics

Monday, February 16, 2009

Cloudy East, Sunny West

If you needed proof that western Washington can be sunnier than eastern Washington in the winter...today is a good example. Look at the latest satellite picture. The east side is covered in low clouds, which are pushing into the Cascade passes (sorry, lots of clouds at the ski resorts in the pass). West of the crest, there is sun in many locations...with the south Sound still in fog and low clouds and the remainder of yesterday clouds/rain over NW Washington (see radar). But both of these locations should improve during the day with sun reaching most of western Washington. The real weather is to the south over Oregon and particularly California...where heavy rain and strong winds are hitting. The rest of the week....more of the same for us. The upper pattern is absolutely amazing...with a very deep low center over the eastern Pacific...this is quite unusual.

25 comments:

He meant both the S. Sound and E. Washington where the stratus has presisted will lift like it already has in Spokane. i.e. conditions improving as in those areas where the low clouds were present at the time of posting.

Isn't that low pretty good sized? It seems like it should affect us (W WA) when it moves inland. Or all the 'weather' is located in the southern half of the low. I am one to think there is always more that can be said about this 'boring' weather we are having (since it seemed like kind of a beautiful day, actually).

Hey Cliff...about the long range. Yeah, I know things can change in the long range. That is a given. But I`m not trying to get folks excited, just merely telling in my own words of what the longer range shows. Thats all. :o)

On a side note...Pretty nice day today with high of 48. Had some early morning fog, then skies were mainly sunny until about mid-late afternoon. Skies became mostly cloudy during that time. But pretty nice over all.

Well hard to say. Best advice I can say right now is just to keep checking the daily models and take them with a grain of salt as they have been toying around with the idea. So at times, yeah, marginally cold enough for snow. But don`t get your hopes up. :o)

Ya...keep checking those models daily! Last week they were showing that it was supposed to be breezy and rainy today...? I for sure don't trust those long range, unless they are all in agreement and for more than one run...but even then they can change their minds! They can even change their minds when it's only a couple of days out...so don't get your hopes up for cold or snow! Actually, as much as I love stormy weather, I am soooooo ready for spring and warmer temps. If it's going to be as boring as it has been then lets warm it up!

Beware of long range models as they tend to trend cold then trend warmer... This trend has accrued two other times over the last two months and it has not played out yet. We need to see some consistency first for a number of runs and even then it is not a slam dunk. Beware these models and more than likely it WIll not stay cold.. But you can always HOPE! :)

I meant what does Cliff mean by "improve"? You used the word "improving" again, which doesn't tell me what he means. What you said about the stratus "lifting" doesn't explain it either. The persisting stratus seems like a great thing - is it not?

Very interesting water vapor satellite image late Monday evening: an unusually small, but distinct upper low just of the northwest Washington coast.We`ll see if it opens up and impacts our weather at all on Tuesday, or just dissipates.

Cliff: I really enjoy your blog. Thank you so much for sharing your knowledge and insight with us. Can you provide a little more detail on the mechanics of why we are experiencing the current weather pattern? The way I understand it a “low” off the coast is diverting the jet stream and associated weather to the south? Can you provide some additional insight in layman’s with regards to this situation? Thanks!

Latest GFS show this week to remain dry through about Sat, but come Sun, it appears a strong area of low pressure will take shape off the west coast and move inland over WA or Oregon for late Sun into Mon. This will likely be a cool and showery day with thicknesses in the lower 520`s and 850mb temps of -3 to -6c with S-SELY flow just above the surface. So highs probably in the 40`s for Sun/Mon. But after the weekend, it looks like the GFS models are more or less going back to the idea of a weak split flow type pattern, but at the same time trying to go with the idea of a trough and unsettled pattern. GEM models seems to be a little more splittly while the 00zEURO and MRF is more or less troughy after the weekend. So models not really sure exactly on how to handle the weather pattern after this weekend. So keep looking at the models as always.

One of the best ways I have found to reveal a trend in the extended forecast is to do this: Run a loop off the extended WRF-GFS, for instance look at the 300mb isotachs (which is a good way to reveal the strength of the weather pattern where other methods can be deceptive, especially for cut off lows). Run the loop and note a change in pattern or an interesting system. For instance right now around 120hrs the cut off kicks out and as a northern stream shortwave drops in, the pattern looks a lot more energetic. Then, go back and select that time, just by itself--no loop. Finally, use the dprog dt featuere to see how the model has changed over time. The UW provides a great service with that dprog dt feature, much appreciated! --MM

Hi Joe. Thanks for the comment as well as to the anon posted at 1251pm. :o)

Anyway Joe, when I meant strong area of low pressure, I just meant that it appeared stronger than what previous systems have came through. Could of used the phrase 'deep low', but that would of been over kill.

From what is show in the latest models, the GFS 18z and UKMET model keep us dry through about Sat. But then Sun, we may have a few showers in places as an area of low pressure will be off shore. However, it appears that models may be trending further westward with wide area of low pressure, and thus, not much of an impact on us. But will likely still see some clouds and sun at times and may very well be mostly dry with the low so far off as we have S-SELY flow aloft over the weekend. On the flip side, 12zEURO has some ridging over us which if taken for granted, would for sure give us at least a partly sunny weekend with highs probably in the low or mid 50`s as 500mb heights on the EURO are shown to be in the mid 550`s. Even the WRF is showing a ridge for late week. So it may very well end up being a dry and maybe perhaps a decent weekend.